1. Field of the Invention
This invention relates to insulation resistance measuring apparatus and, more specifically to such apparatus which can be operated without shutting down the transmission system in which the insulation resistance is being measured.
2. Prior Art
In the past, insulation resistance has been measured with high voltage, low current generators, sometimes referred to as "meggers". Alternatively, other systems have been provided which have not been capable of operating in grounded transmission line systems, such as the single-phase, two or three wire systems commonly used to provide power to domestic users. Meggers cannot be used with the power line "hot", i.e. operational. The inherent high distributed capacitance in power line systems defeats the other prior art insulation measuring apparatus.